KR100729753B1 - Optical apparatus and image-taking system - Google Patents

Abstract

The present invention discloses an optical device capable of performing high-speed and high-density focus detection by the TTL phase difference detection method and the same division method. The optical apparatus has a first optical element. The first optical element divides the first polarized light component included in the light passing through the exit pupil of the first optical system toward the photoelectric conversion element so as to face another light receiving region on the photoelectric conversion element. In addition, the other optical device is a first optical element for dividing the first optical component included in the light that passes through the exit pupil of the first optical system toward the photoelectric conversion element toward the other light receiving region on the photoelectric conversion element, and It has a 2nd optical element which isolate | separates the 2nd optical component contained in the said light from a 1st optical element with respect to the said 1st optical component.

TTL, phase difference, optical system, optical instrument

Description

OPTICAL APPARATUS AND IMAGE-TAKING SYSTEM}

1 is a schematic diagram showing the configuration of a camera system according to Embodiment 1 of the present invention;

2 is a schematic view showing an optical path in Example 1;

3 (a) to 3 (d) are explanatory views showing the structure and manufacturing method of the optical deflecting element in Example 1;

4 (a) and 4 (b) are schematic diagrams showing optical paths at the time of focus detection and finder observation in Example 1,

5 is an explanatory diagram showing a principle of focus detection in Example 1;

6 is a schematic diagram showing a configuration of a camera system of Embodiment 2 of the present invention;

7 is a schematic view showing the configuration of a conventional camera system.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical apparatus for performing automatic focusing (AF) using a photoelectric conversion element.

In the single-lens reflex type digital still camera, the so-called equal division method is adopted to enable accurate focus detection even for a fast-moving subject.

Fig. 7 shows a schematic configuration of a conventional single-lens LEF type digital still camera system. When the photographer observes the subject through the eyepiece 104, a part of the light 110 from the subject passing through the photographing lens 120 is reflected by the main mirror 101 installed in the camera body 100. The subject image is formed on the focus plate 102. The subject image formed on the focus plate 102 reaches the photographer's eye via the pentathaprism 103 and the eyepiece 104.

A part of the light 110 from the subject passes through the main mirror 101, reflects off the submirror 105, and reaches the focus detection unit 106. The focus detection unit 106 is composed of a field lens, a reflecting mirror, an aperture mask, a secondary imaging lens, a light receiving sensor, and the like, and the light receiving sensor receives a light beam passing through another moving area of the photographing lens 120. Then, a phase signal is output from each of the pair (or plural pairs) of line sensors constituting the light receiving sensor. Then, the focus state (defocus direction and defocus amount) of the photographing lens 120 can be detected based on the phase difference of the image signal. In addition, the driving direction and driving amount of the focus lens 123 of the photographing lens 120 are calculated from the detected focus state, and the focusing state can be obtained by driving the focus lens 123.

At the time of imaging, the main mirror 101 and the submirror 105 evacuate out of the optical path, and the light from the subject passing through the imaging lens 120 reaches the image sensor 108.

By the way, the TTL (Through the Taking Lens) phase difference detection method and the same-dividing focus detection method require a sensor for focus detection or a secondary imaging optical system, making it difficult to miniaturize the camera and reduce the cost.

In recent years, a digital still camera has been proposed that performs focus detection using the TTL phase difference detection method and the same division method using an image sensor provided for photographing a subject. For example, Japanese Patent Laid-Open No. 9-43507 discloses inserting a mask through which light from a part of the motion passes in the vicinity of a pupil of a photographing lens, and changing the opening position of the mask. Focus detection is performed using a signal from an image sensor corresponding to the two formed images.

In addition, a focus detection system has also been proposed, in which part of the image sensor is a sensor area for AF and guides two beams divided by a split image prism provided in the photographing optical system to the area (Japanese Patent Laid-Open No. 2004). -46132 publication).

Moreover, the structure which implements TTL phase difference system AF by arrange | positioning a holographic optical element on the object side rather than a primary imaging surface is also proposed (Japanese Unexamined-Japanese-Patent No. 4-147207).

However, in the focus detection method proposed in Japanese Unexamined Patent Application Publication No. 9-43507, the image of the image sensor output (image signal) is changed by changing the opening position of the mask so that the image of the light passing through the other dynamic region of the photographing lens is changed. It reads twice, compares these phase signals, and performs focus detection. For this reason, it takes some time to change the opening position of the mask and to read the two phase signals from the image sensor, which is somewhat unsatisfactory for the ultra-checkout of a fast-moving subject.

In addition, in the method of using the split image prism proposed in Japanese Patent Laid-Open No. 2004-46132, unlike the TTL phase difference detection method, a larger image than the split image prism is required. In addition, if the shape on the boundary line of the split image prism is not a straight line, there is a limitation in performing the focus detection, such as determining that the image is not focused even in the focusing state, thereby obtaining a focus detection performance equivalent to that of the TTL phase difference detection method. Can't.

In addition, the method of using the holographic optical element proposed in Japanese Patent Laid-Open No. 4-147207 is the same as the TTL phase difference detection method in principle, but in the same division direction, which is important for determining the focus state. When forming two images (AF images), since a holographic optical element having a large color dispersion is used, an image with little aberration cannot be obtained, which is not practical for performing focus detection.

An object of the present invention is to provide an optical apparatus capable of performing high-speed and high-density focus detection by the TTL phase difference detection method and the same division method.

An optical apparatus as one aspect of the present invention has a first optical element. The first optical element divides the first polarization component included in the light passing through the exit pupil of the first optical system toward the photoelectric conversion element to face another light receiving region on the photoelectric conversion element.

In addition, an optical device according to another aspect of the present invention includes a first optical component that splits a first optical component included in light that passes through the exit pupil of the first optical system toward the photoelectric conversion element to face another light receiving region on the photoelectric conversion element. An optical element and a second optical element for separating a second optical component contained in the light from the first optical element with respect to the first optical component.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described, referring drawings.

Example 1

1 shows a schematic configuration of a single-lens lef type digital still camera system according to an embodiment of the present invention. In addition, the same code | symbol as FIG. 7 is attached | subjected to the component common to the conventional camera system shown in FIG.

Reference numeral 300 denotes a camera body (optical device), and a mount lens 120 of the camera body 300 is mounted with a photographing lens 120 (interchangeable lens) via a lens mount 121.

The photographing lens 120 includes a photographing optical system 125 as a first optical system constituted by a plurality of lenses including a focus lens 123 and an aperture 124, and a lens control circuit such as an MPU not shown in the drawing. Is installed. The lens control circuit can communicate with a camera control circuit 309 such as an MPU installed in the camera body 300 via the lens side contact 122 and the camera side contact 112. The camera control circuit 309 has an image processing function for generating a subject image on the basis of a signal from the image pickup device 108 described later, and at the same time based on a signal from the image pickup device 108, It also has a focus detection function that detects the focus state of 125 and calculates the driving amount of the focus lens 123.

In the camera main body 300, reference numeral 200 denotes an optical deflection element that is a first optical element, and its specific configuration will be described later. Reference numeral 108 denotes an imaging element (image sensor) as a photoelectric conversion element composed of a CCD sensor, a CMOS sensor, or the like, and a polarizing beam splitter serving as a second optical element between the optical deflection element 200 and the imaging element 108. 301 is disposed. In addition, an infrared cut and a low pass filter 107 are disposed just before the imaging element 108.

Reference numeral 102 denotes a pint plate, 103 denotes a pentathaprism guiding the image of an object formed on the pint plate 102 to the eyepiece 104. These pint plates 102, pentadhaprism 103 and the eyepiece 104 ) Constitutes a finder optical system as a second optical system.

2 shows an optical path at the time of detection (focus detection) of the focus state of the photographing optical system 125 in the camera system.

Light 110 from the subject passing through the imaging optical system 125 first enters the optical deflecting element 200. The light 110 is unpolarized light. In the optical deflection element 200, a part of the first polarization component 211 (hereinafter referred to as + deflection light) in the light 110 having a polarization plane parallel to the zx plane in the drawing is in the + y direction in the drawing. Deflect and transmit. The polarization beam splitter 301 has a property of transmitting the first polarization component and reflecting the second polarization component having a polarization plane orthogonal to the z-x plane in the drawing (that is, parallel to the y-z plane).

For this reason, the + -polarized light 211 of the first polarized light component passes through the polarization beam splitter 301 and collects light in the upper light receiving area of the image of the image pickup device 108. In addition, a part of the first polarization component 212 (hereinafter referred to as -deflection light) is deflected in the y direction in the figure, is transmitted through the polarization beam splitter 301, and is shown in the lower light receiving region of the image pickup device 108. Light gathers in

The + deflected light 211 and the-deflected light 212 of the first polarized light component that has reached the imaging device 108 are light that has passed through other regions in the exit pupil of the imaging optical system 125. For this reason, a pair of images are formed on the imaging device 108 by these + -deflected light 211 and --deflected light 212, and the output signal from the imaging device 108 corresponding to the pair of images ( Based on the image signal), the focus detection using the same division method can be performed.

On the other hand, the second polarization component 210 included in the light 110 passes through the optical deflection element 200 as it is, and is reflected by the polarization beam splitter 301 as the second optical element to reflect the pint plate ( 102) Light is collected on the subject to form an object image. Accordingly, even when focus detection is performed using the first polarized light component (+ deflected light 211 and-deflected light 212), the photographer can observe the subject image through the finder optical system.

Here, the configuration and manufacturing method of the optical deflection element 200 will be described with reference to FIGS. 3A to 3D. As shown in Fig. 3 (d), the optical deflecting element 200 is formed on the resin substrate 201 having the blazed diffraction grating sequentially formed from the light incidence side and the grating structure (the valley part) of the diffraction grating. It consists of the liquid crystal 202 arrange | positioned, the polarizing film 204 in which the opening 204a, 204b was formed in a part as shown in FIG. 3 (c), and the glass substrate 203 which can attach the said polarizing film 204. It is.

As shown in Fig. 3 (a), the resin substrate 201 is provided with first grating gratings 201a and second grating gratings 201b having the same lattice groove direction and different blazing directions. These blazed diffraction gratings 201a and 201b are manufactured by a molding method using a mold integrally with the resin substrate 201.

The grating grooves of both diffraction gratings 201a and 201b in the resin substrate 201 are filled with a liquid crystal 202 which is a uniaxial translucent material as shown in Fig. 3B. Here, the phase refractive index no of the liquid crystal 202 is selected to substantially match the refractive index ng of the resin substrate 201.

First, an alignment film such as polyimide is applied to the surfaces of the diffraction gratings 201a and 201b to perform alignment treatment. Next, the solvent is blown by filling the lattice groove with the UV curable liquid crystal 202 and heating, and then irradiated with ultraviolet rays to cure the liquid crystal 202. At this time, the molecular axis of the liquid crystal polymer is aligned so as to be substantially parallel to the lattice groove direction (x direction) of the diffraction gratings 201a and 201b. In FIG.3 (b), the molecular axis of a liquid crystal polymer is shown in rod shape. The molecular axis direction of the liquid crystal polymer and the optical axis direction with respect to polarization are substantially coincident.

The liquid crystal 202 is filled in the lattice groove, and the glass substrate 203 to which the polarizing film 204 can be attached may be bonded to the liquid crystal 202 side of the cured resin substrate 201. The openings 204a and 204b formed in the polarizing film 204 are disposed in regions corresponding to the diffraction gratings 201a and 201b, respectively. The openings 204a and 204b are disposed at positions symmetrical with respect to the y-z plane including the optical axis (z axis). The polarizing film 204 is disposed such that its polarization axis (optical axis) direction is substantially orthogonal to the optical axis direction of the liquid crystal 202 filled in the grating groove.

Next, a method of performing focus detection in the same division method while observing a subject image with a finder optical system will be described using Figs. 4A and 4B.

4 (a) and 4 (b) show a second polarization component 210 that can be used for finder observation and a first polarization component that can be used for focus detection (+ polarized light 211 and -polarized light 212). It shows how to separate.

4A shows an optical path of a plane orthogonal to the z-x plane passing through the center of the opening 204a of the polarizing film 204 provided in the optical deflection element 200. Light (first and second polarization components) passing through a partial region (first region) of the exit pupil of the photographing optical system 125 and passing through the diffraction grating 201a through the opening 204a of the polarizing film 204. This is incident. The polarization axis direction of the polarizing film 204 is set to absorb the first polarization component having a polarization plane parallel to the z-x plane in the figure.

The molecular axis of the liquid crystal 202 disposed in the grating groove of the diffraction grating 201a is oriented so as to be substantially parallel to the grating groove direction (x direction). With respect to the refractive index ng of the resin substrate 201, the ideal refractive index ne of the liquid crystal 202 is

ne> ng ... （1)

Since the relationship between the first polarization component having a polarization plane (polarization plane parallel to the z-x plane) substantially parallel to the molecular axis of the liquid crystal 202 is deflected in the + y direction in the figure. A part of the first polarization component transmitted through the liquid crystal 202 is absorbed by the polarization film 204, but the + polarized light of the first polarization component transmitted through the opening 204a of the polarization film 204 and the glass substrate 203 Reference numeral 211 penetrates through the polarization beam splitter 301 and reaches the upper light receiving region of the image of the imaging device 108.

For example, when the refractive index ng of the resin substrate 201 is 1.5, the abnormal refractive index ne of the liquid crystal 202 is 1.7, and the required deflection angle φ of the + deflected light 211 is 8 °, the diffraction gratings 201a and 201b are used. The desired deflection angle φ can be obtained by setting the lattice pitch p of 4 mu m and the inclination angle θ of the resin substrate 201 to 35 degrees.

4B, the optical path of the surface orthogonal to the z-x plane passing through the center of the opening 204b of the polarizing film 204 provided in the optical deflection element 200 is shown. Light (first and second polarization components) passing through another partial region (second region) of the exit pupil of the imaging optical system 125 is incident on the opening 204b of the polarizing film 204.

The molecular axis of the liquid crystal 202 disposed in the lattice groove portion of the diffraction grating 201b is oriented so as to be substantially parallel to the lattice groove direction (x direction), and the refractive index ng of the resin substrate 201 and the abnormality of the liquid crystal 202. Since the refractive index ne has a relation of the above formula (1), the first polarization component having a polarization plane (polarization plane parallel to the zx plane) substantially parallel to the molecular axis of the liquid crystal 202 is in the -y direction in the figure. Is biased. A part of the first polarization component transmitted through the liquid crystal 202 is absorbed by the polarization film 204, but the -deflection of the first polarization light component transmitted through the opening 204b of the polarization film 204 and the glass substrate 203. The light 212 passes through the polarization beam splitter 301 and reaches the lower light receiving region in the drawing of the image pickup device 108.

On the other hand, with respect to the refractive index ng of the resin substrate 201, the phase refractive index no of the liquid crystal 202 is

no ≒ ng ... (2)

Since the second polarization component 210 having the polarization plane (polarization plane parallel to the yz plane) orthogonal to the molecular axis of the liquid crystal 202 is subjected to the deflection action of the diffraction gratings 201a and 210b. Go straight. The second polarization component 210 is reflected by the polarization beam splitter 301 to collect light on the focus plate 102 to form an object image. The subject image formed on the focus plate 102 is observed by the photographer through the pentathaprism 103 and the eyepiece 104.

Next, the principle of focus detection using the + deflected light 211 and the-deflected light 212 will be described with reference to FIGS. 5A and 5B. 5A shows an optical path in a focusing state with respect to a subject having the photographing optical system 125. Of the light transmitted through the imaging optical system 125 and incident on the optical deflecting element 200, it is a first polarization component having a polarization plane parallel to the zx plane in the figure and passes through the openings 204a and 204b of the polarization film 204. The + deflected light 211 and-deflected light 212 pass through the polarization beam splitter 301, which is omitted in FIG. 5, and then form an image on the image pickup device 108. At this time, in the image pickup device 108 corresponding to the two phases formed by the + -deflected light 211 and-deflected light 212, the phase signal from two predetermined lines extending in the x direction is shown in FIG. As shown.

The + deflected light 211 and the-deflected light 212 pass through different areas in the exit pupil of the photographing optical system 125, but because the photographing optical system 125 is in focus with respect to the subject, the aperture ( The image (phase signal) A formed by the + deflected light 211 passing through 204a and the image (phase signal) B formed by the -deflected light 212 passing through the opening 204b are the imaging elements 108. ) Is aligned in the x direction.

5B shows an optical path when the photographing optical system 125 is in a so-called all-pin state with respect to the subject. The positive deflection light 211 and the negative deflection light 212 form an image once in front of the image pickup device 108 and then diverge to reach the image pickup device 108. At this time, the phase signals from the two lines corresponding to the two phases formed by the + deflected light 211 and the-deflected light 212 are as shown in Fig. 5E.

Since the photographing optical system 125 is in the front pin state, the image (phase signal) A formed by the + deflection light 211 passing through the opening 204a and the -deflection light passing through the opening 204b. The image (image signal) B formed by 212 is shifted in the -x direction of the imaging element 108. For this reason, the defocus direction (front pin direction) and the defocus amount of the photographing optical system 125 are determined by the camera control circuit 309 shown in FIG. 1 based on this shift direction and the positional relationship (phase difference) between the images A and B. Is detected.

5C shows an optical path when the photographing optical system 125 is in a so-called rear pin state with respect to the subject. The positive deflection light 211 and the negative deflection light 212 reach the imaging device 108 in a state where the luminous flux is widened. At this time, the phase signals from the two lines corresponding to the two phases formed by the + deflected light 211 and the-deflected light 212 are as shown in Fig. 5 (f).

Since the photographing optical system 125 is in a post pin state, the image (image signal) A formed by the + deflection light 211 passing through the opening 204a and the -deflection light passing through the opening 204b. The image (image signal) B formed by 212 is shifted in the + x direction of the imaging element 108. For this reason, the defocus direction (post pin direction) and the defocus amount of the photographing optical system 125 are determined by the camera control circuit 309 shown in FIG. 1 based on the shift direction and the positional relationship (phase difference) between the images A and B. Is detected.

The camera control circuit 309 calculates the driving direction and the driving amount for obtaining the focusing state of the focus lens 123 shown in FIG. 1 based on the detected defocus direction and the defocus amount, and controls the lens not shown in the figure. The driving of the focus lens 123 is controlled through a circuit.

In addition, since the optical deflecting element 200 of the present embodiment has a polarization characteristic, when the object has a polarization characteristic, it is affected. Therein, in order to remove the polarization characteristic of the subject, a 1/2 wavelength plate is provided on the light incidence side of the optical deflection element 200, and a polarization plane (polarization direction) of light incident on the optical deflection element 200 is required. It is desirable to rotate according to.

As described above, after performing the focus detection and AF control together with the observation of the lens, when the image pickup device 108 captures the subject image, the optical deflecting device 200 and the polarizing beam splitter 301 are photographed by the optical system 125. Evacuate out of the optical path between the imaging elements 108.

As described above, according to the present embodiment, focus detection can be performed by using an image pickup device while checking a subject by a finder optical system, and a sensor or optical system dedicated to focus detection is not necessary, thereby miniaturizing the camera, The cost can be reduced.

In addition, since two images are formed on the image pickup device by two luminous fluxes deflected by the optical deflecting element, focus detection is possible by reading a single image signal from the image pickup device, so that the focus detection can be accurately performed even on a fast-moving subject. Can be done.

Further, since the optical deflecting element deflects light passing through the other moving region of the photographing optical system in different directions, it is possible to perform focus detection using the TTL phase difference detection method and the same division method based on the images formed by the deflected light. .

In addition, the optical deflection element is deflected to form the focus detection image for the first polarization component, and the second polarization component is transmitted as it is, thereby forming a binder image by the second polarization component. It is possible to obtain a finer image without distortion.

In addition, by forming the binder image with the second polarization component which is transmitted through the optical deflecting element as it is and reflected by the polarization beam splitter, the decrease in the amount of light on the binder can be suppressed.

In addition, by allowing the polarizing beam splitter and the optical deflecting element to be evacuated out of the optical path between the photographing optical system and the image capturing element, it is possible to capture a subject image without distortion or light amount deterioration by the polarizing beam splitter or the optical deflecting element.

In addition, since the optical deflection element is composed of the first and second blazed diffraction gratings having different blaze directions, the uniaxial transmissive material, and the polarizing film, it is possible to provide an inexpensive optical element for performing the focus detection of the same division method. Can be.

Example 2

In Example 1, the case where both the optical deflecting element 200 and the polarizing beam splitter 301 are provided in the camera main body has been described. However, as shown in FIG. It may be arranged at the same position in the (interchangeable lens) (the position of the stop 124) or its vicinity.

In addition, in the said Example 1 and 2, although the lens interchangeable single-lens LEF camera system was demonstrated, this invention can be applied also to other camera systems (for example, a lens integrated camera system).

In the above embodiments, the optical deflecting element 200 has described a case in which some of the first polarization components are deflected in the + y direction and the other in the -y direction, respectively. The imaging element 108 may be reached without deflecting this. In this case, the pair of images is formed, for example, on the top and the center of the imaging device.

In addition, in each of the above embodiments, the case where the + deflected light 211 and the-deflected light 212 are deflected in the same direction as the dividing direction of the same area of the photographing optical system passed by them has been described. The deflection direction is not limited to this.

In the above embodiments, the case where two images are formed on the image pickup device 108 by the two deflected lights 211 and 212 has been described. However, the number of deflected lights and the deflection of the deflected light so as to form more than four images are explained. You can also increase the direction.

In the above embodiment, the case where the optical deflecting element 200 having the blazed diffraction grating is used has been described. However, in addition to the blazed diffraction grating, an element having a function of deflecting the light beam and generating less aberration is used. It is also possible to create an optical deflection element. The optical deflecting element shown in the above embodiment has been described in the case where the liquid crystal is arranged in the grating groove of the diffraction grating, but the arrangement relationship between the diffraction grating and the liquid crystal is not limited to this, and the member which encloses the liquid crystal between the glass substrates. May be disposed adjacent to the diffraction grating (resin substrate).

In addition, in the above embodiment, a case has been described in which the optical deflecting element 200 which divides a part of incident light by using polarization characteristics and forms two phases on the imaging element 108 is used. As the element, an optical deflecting element for dividing a part of incident light by using optical characteristics (for example, wavelength characteristics) other than polarization characteristics may be used.

As described above, according to each of the above embodiments, since a pair of images are simultaneously formed on the photoelectric conversion element by dividing the first polarization component incident on the first optical element, it is compared with the case of changing the opening position of the mask. The phase signal can be obtained at high speed. In addition, compared with the case of using a split image prism or a holographic optical element, it is possible to form a pair of images with less aberration suitable for focus detection. Therefore, the high-speed and high-density focus detection can be performed by the same division method while being the TTL phase difference detection method.

In addition, by separating the second light component (for example, the second polarization component) included in the light from the first optical element from the first light component (for example, the first polarization component) toward the photoelectric conversion element, Only the pair of phases can be formed on the photoelectric conversion element, and the second light component can be used for other applications such as finder observation.

Claims (13)

The first polarization component included in the light passing through the exit pupil of the first optical system 125 toward the photoelectric conversion element 108 is formed to form an image in different regions on the photoelectric conversion element. A first optical element 200 to be divided, And detection means for detecting a difference in phase of an image formed in said other area. The method of claim 1, The first optical element may include a plurality of diffraction gratings 201a and 201b each having a blaze shape and different in the blaze direction, Optical device having a uniaxial translucent material portion having a specific optical axis direction. The method of claim 2, And said first optical element further comprises a polarizing film (204) having a plurality of opening regions while having a polarization axis direction orthogonal to an optical axis direction of said uniaxial translucent material portion. The method of claim 1, The first optical element directs the first polarization component passing through the first region in the exit pupil toward the first light receiving region on the photoelectric conversion element, and passes through the second region in the exit pupil. And directing the first polarization component toward a second light receiving region on the photoelectric conversion element. The method of claim 1, And the photoelectric conversion element, having an image pickup element for photographing an object image formed by the first optical system. The method of claim 1, And a focus detecting device for detecting a focus state of the first optical system based on an output from the other light receiving region. The method of claim 1, And a second optical element (301) for separating a second polarization component contained in said light from said first optical element with respect to said first polarization component. The method of claim 7, wherein And said second optical element injects said second polarization component into a second optical system (103, 104). The method of claim 7, wherein And the first and second optical elements are movable in and out of an optical path from the first optical system toward the photoelectric conversion element. A lens device having a first optical system 125, An optical system as an image pickup apparatus according to any one of claims 1 to 9, wherein the lens apparatus is mounted. The first optical element 200 for dividing the first optical component included in the light passing through the exit pupil of the first optical system 125 toward the photoelectric conversion element 108 to form an image in different regions on the photoelectric conversion element. )Wow, Detecting means for detecting a difference between phases of an image formed in the other region; A second optical element 301 which separates a second optical component included in the light from the first optical component with respect to the first optical component; And a second optical system (103, 104) for observing an image formed by said second optical component separated by said second optical element. delete A lens device having a first optical system 125, An optical system as the imaging device according to claim 11, wherein the lens device is mounted.

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